Functional diagram of the föehn effect on the southern façade of the Iberian Peninsula.
The article here on the La Voz de Almería site is the fourth in the series.
Read More for a Google translation of the article.
Almería stories about the landscape (IV): A Mediterranean lee
A series that aspires to intervene in the perception of geographical and territorial reality
Among the climatic variables that have drawn our attention since time immemorial, the wind is a recurring and controversial issue. It is recurrent because of the importance it has in our lives and activities. It is conflictive due to its subtle nature, and due to the confusion that exists between the different mechanisms that generate air movement. Also due to the frequent attempt to define a wind by the local and even personal effects that it produces. Neither does the use of local terms to name the different air movements contribute to greater clarity.
In short, a great song, which, as my kind readers will imagine, is not approachable in depth in this humble series from Virado to Cuttlefish. But geographers are supposed to have a certain capacity for synthesis to narrate complex processes. Go for it.
Almería is, among many other things, a Mediterranean leeward. Affirmation of such caliber requires certain clarifications. The arrangement of the mountains and mountain ranges in the south of the Iberian Peninsula allows us to distinguish between the humid mountain ranges, located in the western area (Grazalema, Alcornocales, Ronda, Tejeda ...) and the dry mountains, all of them located in the eastern zone (which significantly coincides with the province of Almería). This distribution, which is clearly indicated by the fact that the maximum rainfall of the peninsula is in the Sierra de Grazalema (Cádiz), and the minimum in that of Cabo de Gata, is due to the predominance of western situations in our latitudes. Moist air masses from the Atlantic interact with the bumps, which accelerate precipitation on the windward slopes (those that directly receive that air mass), while drastically reducing it on the leeward slopes (those that turn their backs on it) . This is known as the foehn mechanism or effect. This German designation of origin (föehn means hair dryer) was originally applied to explain the climatic differences that were observed in the region of the Swiss Alps, depending on the hillside orientations.
Precipitation forecast in a western situation (Photo: VENTUSKY APP SCREEN CAPTURE).
We already know in what sense we can affirm that we are a leeward, which also explains our structural aridity. It remains to explain why we are a Mediterranean leeward. When Javier de Burgos drew the limits of the organization in the provinces (in 1822 the process began, interrupted by the absolutist reaction, until in 1833 they were re-established, to this day), a large section of the western limit with the province of Granada was established with hydrological criteria, separating the Atlantic from the Mediterranean. In that section that extends between Sierra Nevada and Sierra de María, the provincial limit separates the waters that will go to the Guadalquivir, and, therefore, will flow into the Atlantic, together with Sanlúcar de Barrameda, from those that will go to the Mediterranean through a set of basins, the Andarax, Alías, Aguas and Almanzora rivers.
Among the Andalusian provinces, Almería and Málaga are almost entirely Mediterranean; Cádiz, Granada and Jaén have a small Mediterranean part, although they are mostly Atlantic, while Córdoba, Seville and Huelva are entirely Atlantic.
The name of the winds
In our Mediterranean leeward, the winds, which are classified according to their origin, are called in the main quadrants with the universal names of North, South, East (Levante) and West (Poniente). The intermediate quadrants, with the classical names of Mediterranean navigation Grecal (from Greece, NE), Sirocco (from Syria, SE), Lebeche (from Libya, SW) and Mistral (from Venice, master republic, NO). To understand these denominations, it must be taken into account that they were established in a nautical point located between Malta and Crete.
Atlantic and Mediterranean basins in Andalusia.
Wind and temperature
But one thing is where the wind comes from, and another thing is what local characteristics it has. The paradigmatic example of this fact, which generates astonishment among its "mourners" is that the east is dry and warm in the city of Almería, while it is humid and cool on the Nijar coast. Are they different winds? No. What are different are their local characteristics, which are conditioned by their position with respect to the sea and the mountains. It is enough for the cool and humid wind from the Nijaran coast to cross the area known as El Hornillo (we have here a plausible hypothesis of the origin of said place name), for it to reach the city of Almería, advising the enclosure. What is truly curious about this phenomenon is that the change in the conditions of that air occurs only in the layer closest to the earth's surface, which is where we live.
Wind and air
In a strict sense, the wind is the movement of air produced by atmospheric pressure differences, while the breeze (also called air, simply) is produced by temperature differences, motivated by the land-sea thermal balance, and its different rhythm cooling and heating. It is good to call every movement of the air wind, but it is better to know that behind this movement there are different causes. To know what wind is going to be, you have to check the weather information; breezes, on the other hand, are predictable from experience, since they respond to verifiable local mechanisms.
Compass rose in the Mediterranean, as defined at a point between Malta and Crete.
As in any physical-environmental process, its knowledge and understanding requires a certain scientific capacity, but its empirical discovery by lay people helps a lot to pay attention to the human artifacts that interact with these natural processes. Observation of the location of windmills (we should call them airmills, for the reasons explained here), or modern wind farms, clearly indicates how local geography interferes with meteorological conditions, turning them into climatic ones.
Next week, we will delve into the fascinating topic of water governance.